XML 124 R110.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Commitments and Contingent Liabilities - Summary of Financial Instruments with Off-Balance-Sheet Risks (Detail) - USD ($) $ in Thousands | Dec. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Commitments And Contingencies Disclosure [Abstract] |  |
Loan commitments | $ 981,777 | $ 960,490
Stand-by letters of credit | $ 56,551 | $ 61,889

X
- Definition Standby letters of credit. + References No definition available. + Details
Name: | banf_StandbyLettersOfCredit
Namespace Prefix: | banf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unfunded loan commitments. + References No definition available. + Details
Name: | banf_UnfundedLoanCommitments
Namespace Prefix: | banf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration